Devices for examining potentially diseased areas of the body have been used for many years for diagnostic purposes. Magnetic resonance imaging (MRI) machines, ultrasound devices, CAT scanners and X-ray imagers are but a few of the commonly utilized tools that medical radiologists have at their disposal to characterize and understand many of the maladies that afflict patients.
Well-known ultrasound devices use acoustical energy to characterize areas in the body for many different reasons. Particularly useful for displaying fluid flow, acoustical energy detected by ultrasound probes can be used in diverse applications, for example, to examine blood flow in and around diseased tissue, or to investigate the health of a fetus growing in the womb. Since ultrasound devices use acoustical energy to perform their function, they are "active" devices which first emit energy, and then detect reflected energy which has been partially absorbed.
Recently, the development of nuclear probes has given physicians yet another modality to explore and diagnose disease. Nuclear probes are unique and sophisticated devices that take advantage of the fact that diseased tissue tends to absorb substances that emit radiation. Thus, radiopharmaceuticals or radiolabeled monoclonal antibodies (MaB) that emits gamma radiation can be used to label diseased tissues which can then be examined with a nuclear probe.
Generally, the labeled tissue accumulates a higher concentration of the gamma-emitting substance so that the tissue appears "hot" to the probe, that is, more gamma radiation is emitted from the diseased tissue than from other surrounding areas. Since it is known that diseased tissue will more readily absorb the radiopharmaceutical or radiolabeled MaB, the probe thus locates the diseased tissue by detecting the hot area.
A typical nuclear probe that performs along the lines mentioned above is the Radiation Monitoring Devices, Inc. (Watertown, Mass.) Nuclear Surgical Probe System. Primarily for use in surgical applications, the Nuclear Surgical Probe System comprises a solid state Cadmium Telluride (CdTe) detector that detects gamma radiation from about 12 keV to about 1 MeV, a high gain field effect transistor preamplifier, and a counting subsystem with a display which performs diagnostic analysis and which can be interfaced to a personal computer.
Nuclear probes are reliable and innovative devices for locating diseased areas. However, these devices cannot further evaluate the diseased tissue in relation to the patient's anatomy after the tissue has been located. The radiological imaging art has therefore lacked an efficient tool which can both pinpoint the presence of the diseased tissue, characterize the diseased tissue and see its relationship to normal anatomic structures to develop a course of medical and/or surgical treatment.
There has therefore been a failure in the art to develop versatile clinical tools for disease detection and diagnosis. This has resulted in an inability to effectively treat potentially life-threatening diseases at early stages. Early disease detection allows for more effective treatment, significantly improving a patient's prognosis. This ability would not only save lives but contribute to the reduced cost of health care.